What was the online trading system introduced in Pokémon Diamond and Pearl called?

The online trading system introduced in Pokémon Diamond and Pearl was called the Global Trade Station.

Usually abbreviated as GTS, the system allowed players to deposit a Pokémon and request another species in return. Players could also search for Pokémon offered by other users, making it possible to trade beyond the local Game Link Cable or nearby wireless connections.

Diamond and Pearl were released for Nintendo DS and formed the fourth generation of the main Pokémon games. Their online features used Nintendo Wi-Fi Connection, giving players a new way to trade and battle across long distances. This was especially useful because completing a Pokédex traditionally required exchanging Pokémon unavailable in one version.

The GTS was separate from Pokémon Bank, which was a later storage and transfer service. It was also different from the Union Room and later online systems used by newer games. By connecting Pokémon collecting with internet matchmaking, the Global Trade Station became an important step in the series’ move from local multiplayer toward global online communities.